Josh Rojas sparked a five-run, eighth-inning uprising and Daulton Varsho capped it with a three-run homer as the Arizona Diamondbacks rallied for a 6-2 victory over the slumping San Francisco Giants on Tuesday night in Phoenix.

Buddy Kennedy hit a tiebreaking sacrifice fly for the Diamondbacks before Varsho clubbed a 408-foot blast to right-center off Camilo Doval.

Joc Pederson and Austin Wynns drove in runs for the Giants, who have lost a season-worst six straight games and 12 of their past 15.

Arizona trailed 2-1 entering the bottom of the eighth when the left-handed-hitting Rojas, who was pinch-hitting, stunningly dropped down a two-strike bunt single toward third base off Dominic Leone (3-1).

One out later, Rojas moved to third on a single to right-center by Cooper Hummel and then scored when Leone threw a wild pitch.

Ketel Marte and Christian Walker walked to load the bases. Doval replaced Leone and gave up Kennedy's sacrifice fly prior to serving up Varsho's 12th blast of the season.

Mark Melancon struck out two in a perfect ninth in a non-save situation as Arizona defeated the Giants for the second straight day.

Geraldo Perdomo and Varsho had two hits apiece for Arizona, which will seek a three-game sweep on Wednesday.

Wynns drove in a run on an overturned call in the seventh inning to give the Giants a 2-1 lead.

San Francisco's Yermin Mercedes was on second base with two outs when Wynns hit a short fly ball down the left field line off Arizona's Caleb Smith (1-1). Hummel made a sliding attempt near the line, and the ball hit off his left abdomen and was ruled foul by the umpiring crew.

The Giants challenged the call and it was overturned and ruled fair. Wynns was awarded a single and Mercedes jogged home from second with a run that was charged to Noe Ramirez.

Austin Slater had two of San Francisco's six hits.

Giants starter Alex Wood allowed one run and four hits over five innings. He struck out four and walked none.

Tyler Gilbert was recalled from the minors to start for the Diamondbacks, and he gave up one run and four hits over 3 2/3 innings. He struck out two and walked one.

San Francisco opened the fourth inning with consecutive singles by Slater, Wilmer Flores and Darin Ruf. One out later, Pederson hit a sacrifice fly to score Slater.

Arizona knotted the score in the fifth as Carson Kelly hit a ground-rule double to right with one out and scored from third on Perdomo's two-out single to right.

--Field Level Media